The Sex Education Jean baby storyline in season 3 ended with the birth of a baby girl but leaves behind a big question as to who the father is. Following on from the end of Sex Education season 2, Jean's pregnancy becomes one of the major plot threads throughout season 3. It shapes Jean's entire arc as she deals with the various challenges and complications it brings, including the merging of her family with Jakob's (Mikael Persbrandt), the distrust her partner feels, and the near-death experience she has during the birth itself.
https://screenrant.com/sex-education-jean-baby-dad-identity-jakob-remi/